A body of mass m collides elastically with a stationary body of mass M. After collision, m has a speed equal to one-third of its initial speed. Calculate the ratio (m/M).

A body of mass m collides elastically with a stationary body of mass M

1.	A body of mass m collides elastically with a stationary body of mass M. After collision, m has a speed equal to one-third of its initial speed. Calculate the ratio (m/M).
Answer» SOLUTION :`v_1 = ((m_1 - m_2)u_1)/((m_1 + m_2)) ` when ` u_2 = 0` `:. (u_1)/(3) = ((m - M)u_1)/((m + M))` `:. 3M - 3M = m + M or 2m = 4M` or `m/M = 4/2 = 2/1`.